Following the Zabbix restart, a long-running query against the history table was triggered. As a result, the alert action failed to execute properly

1. Why does Zabbix scan the history and history_uint tables after the server restarts?
Why is Zabbix internally scanning historical data (specifically history / history_uint) for individual itemids immediately after the service restarts?
What internal purpose does this serve?

SELECT clock, ns, value FROM history WHERE itemid = 745785 AND clock > 1702790748 AND clock <= 1749510445;
SELECT clock, ns, value FROM history_uint WHERE itemid = 663187 AND clock > 1689304026 AND clock <= 1749458997;

2.How long do these post-restart history scans continue?
We've observed that even after the scan for one itemid completes, Zabbix initiates new scan queries for other itemids.
When (or under what conditions) does Zabbix stop this behavior?
Is there a threshold, completion condition, or configuration parameter that defines when these scans end?

3.During this scan period, metrics are collected and triggers are evaluated correctly — but actions do not execute. Why?
We've confirmed that data collection and trigger evaluation are working normally during this time.
However, actions (such as notifications) are not operated until after the history scans are completed.